| Willoughby to Cadillac (Michigan) | 270.95 mi (436.04 km) |
| Willoughby to Caguas (Puerto Rico) | 1,854.44 mi (2,984.43 km) |
| Willoughby to Cahokia (Illinois) | 509.73 mi (820.33 km) |
| Willoughby to Calabasas (California) | 2,079.46 mi (3,346.57 km) |
| Willoughby to Caldwell (Idaho) | 1,783.36 mi (2,870.04 km) |
| Willoughby to Caledonia (Wisconsin) | 340.29 mi (547.64 km) |
| Willoughby to Calera (Alabama) | 657.23 mi (1,057.71 km) |
| Willoughby to Calexico (California) | 1,961.48 mi (3,156.69 km) |
| Willoughby to Calhoun (Georgia) | 530.21 mi (853.29 km) |
| Willoughby to California (Maryland) | 348.07 mi (560.17 km) |
| Willoughby to California City (California) | 2,008.81 mi (3,232.87 km) |
| Willoughby to Callaway (Florida) | 828.25 mi (1,332.94 km) |
| Willoughby to Calumet City (Illinois) | 317.14 mi (510.39 km) |
| Willoughby to Calverton (Maryland) | 295.09 mi (474.89 km) |
| Willoughby to Camano (Washington) | 2,033.63 mi (3,272.82 km) |
